A close-knit group of New York Jews with Eastern European roots may hold the secret to a long and healthy life — many live to 100 without disease despite smoking, drinking and eating fatty foods.

And researchers in the city are hoping to unlock the code of their genetic jackpot.

Starting in the next few weeks, a team at Cornell Medical College will begin a study of the stem cells of about a dozen Ashkenazi Jews, a heavily persecuted population that descends from Imperial Russia and, through years of intermarriage, shares distinctive genetic traits.

One is a “longevity gene,” which appears to protect them from heart attacks, cancer and other life-threatening maladies.

“The reason they live so long is not because they live healthy lives,” said Dr. Todd Evans, who will lead the study of heart, lung, liver and other cells made from the group’s stem cells at labs on York Avenue.

“Interbreeding can have a negative impact, but, in this case, some families had the opposite effect. They don’t get cardiovascular disease, cancer, neurodegeneration or diabetes or very low rates. And we believe that one aspect to their resistance to disease has a stem-cell base.”

Evans’ team extracts stem cells from the senior citizens’ blood, then transforms them into cells of vital organs that incorporate the healthy gene signatures.

The engineered cells will undergo harsh stress tests, then be examined to see how they fared.

“He’s using the stem cells of centenarians and their children and comparing them with people who are unlikely to get to the age of 100,” said Dr. Nir Barzilai, an aging expert at Albert Einstein Medical School in The Bronx.

For years, he’s tracked hundreds of Ashkenazi Jews for his Longevity Genes Project.

One of the participants, Lilly Port of Scarsdale in Westchester County, turned 98 last Thursday and has never been sick.

She’s too busy traveling — to Italy, Hungary and St. Tropez in the last year alone — to worry about illness.

“I always had good genes,” she said.

Although she doesn’t smoke, this Austrian native enjoys bratwurst, eats chocolate every day and drinks white wine “when I want to relax.”

“I limit my food intake, because I want to be able to fit into my Clothes, but I’m in perfect health,” she said.

Port, who fled Vienna for London at 27 when Hitler invaded, lived on Central Park South till 1950 and has survived three husbands — who died at 92, 97 and 102.

She drove a car until last year.

“Yesterday,” she said, “a woman at the bridge table said, ‘You’re outliving all of us.’ “